*{
    margin:0;
    padding:0;
}

html,body{
    width:100%;
    height: 100%;
    overflow: hidden;
}
.wrap{
    width:100%;
    height: 100%;
    display: flex;
    flex-direction: column;
}

header,footer{
    width:100%;
    height: 44px;
    background: #eee;
    text-align: center;
    line-height: 44px;
}

.con{
    flex:1;
}

ul li{
    width:100%;
    height: 44px;
    line-height: 44px;
    border-bottom:1px solid gray;
}